技術標籤：javajava

定義註解類

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target({ElementType.FIELD,ElementType.METHOD})//作用目標，欄位,方法
@Retention(RetentionPolicy.RUNTIME)//作用範圍，整個執行期間
public @interface
 
 AnnotionBase {
//定義int型欄位，id，預設值為3
    int id() default 3;
// 定義string型別的陣列,stValue
    String[] stValue();
}

反射獲取屬性

package com.ny;

import com.ny.base.annotion.AnnotionBase;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.sql.SQLOutput;

public class App {
    @AnnotionBase
 
(stValue = {"male", "female"})
    public void getUser(String name, int age) {
        System.out.println("user: [" + name + "," + age + "]");
    }
    @AnnotionBase(id = 3, stValue = {"kj"})
    public int age;

    public static void main
 
(String[] args) throws Exception {
        App app = new App();
        Class<? extends App> aClass = app.getClass();

        Field age = aClass.getField("age");
        AnnotionBase annotation1 = age.getAnnotation(AnnotionBase.class);
        System.out.println(annotation1.id()+"id");
        for (String s : annotation1.stValue()) {
            System.out.println("stValue"+s);
        }

        Method getUser = aClass.getMethod("getUser", String.class, int.class);
        getUser.invoke(app,"ff",3);

        AnnotionBase annotation = getUser.getAnnotation(AnnotionBase.class);
        String[] strings = annotation.stValue();
        for (String string : strings) {
            System.out.println(string);
        }
        System.out.println(annotation.id());

    }


}